Once we were able to achieve a working biosensor prototype, our next step was to utilize this in a scenario applicable to embedding in our bioballoon. We decided that cellulose sheets would serve as a satisfactory surface for proof of concept, knowing that later down the road, we could use different binding domains for latex, elastin, collagen, or p-aramid fibers. Conveniently the 2014 Stanford-Brown-Spelman iGEM team had created a Cellulose Cross Linker BioBrick BBa_K1499004 that needed further characterization. We filled this need by purifying the protein (validating the presence of its HisTag), and binding our fluorophore sensor to the linker protein (with quencher). We then distributed this incubated concoction to wax-coated cellulose filter paper to measure the binding activity to the paper over a week. Initially the mixture was applied to the paper and per recommendation 2-3 days is necessary for the cellulose binding domain to take effect. After this initial binding period, 5 x 1 mL of milliQ water (with 1 mM ATP) were washed over each 9-well sample each day for a week. The positive control had the FQ system, but no linker. The negative control had no FQ either.

To learn more please visit our min project page here. Please see our main website Medal Requirements Page for the functional links.